Depending on what kind of Camponotus you pick it might get a little tight - I wouldn't try to put my Camponotus barbaricus (9-18mm) into it but Camponotus nicobarensis (6-12mm) might just fit.

I'd say some of the passages are a bit too small for Camponotus cruentatus majors, but you can just buy your ants and have a look at the queen - if she fits the majors will, too. Since Camponotus usually spend at least half a year in a test tube anyway because they grow so slow you won't really be in a hurry of getting a nest anyway (having a proper outworld is much more important with young Camponotus colonies). Also you could still disassemble the nest and carve out the passages to be a bit larger - modifying Ytong nests is actually quite easy.